The Hacky Easter 2014 was a very fun CTF competition.
I decided to wrote this up because this challenge is kind of basic encode/decode that shoud help someone who want to learn or start to interesting in computer security.
Hacky Easter Challenge 5 need to decode the sniffed email communication.
When I click Download to see the encoded message it’s show as below.
When I see encoded message, I have no idea which algorithm of this email message encoded with, then I start google to some of first character “0M8R4KGxGu”
I am pretty sure it’s base64 encoded message.
so let’s try to decode it!
I have created raw.txt which is the base64 encoded email message.
then I am decode raw.txt to decoded file.
I need to determine file type so I use “file” command.
It’s tell me “Composite Document File V2 Document, No summary info”
again google answer me that it’s outlook message file(.msg)
I copy decoded file to windows box and open with outlook. yes I found the Egg 07 attached in the email.